A little skepticism is a good thing.

I received the email below from a colleague: 

This is the only time you see this phenomenon in your lifetime.

August 2014 will have 5 Fridays, 5 Saturdays and 5 Sundays. This happens only once every 823 years.  The Chinese call it 'Silver pockets full’. It is based on Chinese Feng Shui.

The only time in my lifetime?  Then I had better pay attention!  Right? 

Not so fast.

The guy who sent this to me is reasonably intelligent, a second career professional with a major government organization.  If he had stopped for a  few seconds to think about that "astonishing" claim, he would've realized something was wrong.  I think the “silver pockets full” thing mesmerized him, gave him evocative words and a mental image to distract him from critical thought - much like a magician distracts his audience with dramatic gestures.

According to this email the month of August has five Fridays, five Saturdays and five Sundays only once every 823 years, and this phenomenon is so unusual that it has a special Chinese name.  Now think about it.

I probably would have dismissed the whole thing without thinking it all the way through myself, except that the last day of August happens to be my birthday.  So I thought, "Oh, my birthday is on Sunday this year."  Then I took a step back and did a mental double-take.  "My birthday has been on Sunday before... more than once,”  I thought.  This is particularly memorable to me because when my birthday falls on Sunday, the next day is always Labor Day.

So what did that email say?  That I only get a Sunday birthday once every eight centuries or so?  Let’s think about that.  By the 28^th day of a month, any month, we have already had four of each day of the week (28 divided by 7 is 4).  So the 29^th, 30^th, and 31^st are always the fifth of their own particular day of the week.  

"I know that every time I have a birthday it is on August 31^st,” I thought.  Obviously.  “And I know that every time I have a Sunday birthday there are five Fridays (the 29^th), five Saturdays (the 30^th), and five Sundays (the 31^st) in the month of August." 

Bottom line:  August has five Fridays, five Saturdays and five Sundays, on average, once every seven years - every time August 31^st happens to fall on a Sunday. 

There’s more.  Up to that point I had not considered the other six months with 31 days each.  Hmmm... there are seven months with 31 days each, and whenever the 31^st of any one of those falls on a Sunday it will have five Fridays, five Saturdays and five Sundays.  That means that this five Fridays, five Saturdays and five Sundays thing happens, on average, about once each year.  Not once every 823 years, with a funky Chinese name.

Then there is that “Feng Shui” comment… Doesn’t feng shui have to do with the physical arrangement of objects within an environment?  I may not understand it completely, but I’m pretty sure the focus of feng shui is spatial rather than temporal.  Maybe the writer of this bit of amazing fiction should’ve referred to the Mayan calendar instead.

The morals of the story are these: 

(1) Don’t believe everything you read, especially if it comes to you in an email, and

(2) Pay Attention!  Stop and think before you pass along nonsense.  It clutters our inboxes and our minds, and it doesn't make you look good.

Of course, everything on the Gryphem blog is completely reliable.

- Gryphem